May I suggest start with Large dpn's ( US 10 or up), thick yarn and a good video...that way you can "see" the concept.

I'd recommend large needles and thick yarn for learning (almost) ANY technique. (I'm sure there are exceptions, don't get excited...)

I suspect that DPNs are simply the lowest common denominator, which is why pattern writers favor them. Well, that and probably the really big name pattern writers have probably been doing this for decades or learned at the feet of someone who has, so that's what they know. No tin foil hats required here.

Personally, I'm perfectly content to consign DPNs to the realm of I cord and cables and the occasional piece of flat knitting or repair work. There are times when they're uniquely suited to a particular purpose, but given another option I'll use it. Because I have enough trouble with stitches falling off ONE end of a needle -- I don't need to increase the chances of that happening any further.